Equalizing optical wavelength routers

• US 7,298,540 B2
• Filed: 08/22/2002
• Issued: 11/20/2007
• Est. Priority Date: 08/22/2001
• Status: Expired due to Term

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Avanex Corporation (Oclaro (North America), Inc.)
• Inventors: Li, Ming, Peng, Song
• Primary Examiner(s): Shafer; Ricky D.
• Application Number:
  US10/225,936
• Publication Number:
  US 20040008932A1
• Time in Patent Office: 1,916 Days
• Field of Search: 359/247, 359/250, 359/256, 359/495, 359/496, 359/246, 359/316, 359/485, 359/566, 385/11, 385/24, 385/37, 398/49, 398/84, 398/86, 398/65, 398/87
• US Class Current: 359/256
• CPC Class Codes: G02B 6/2931 Diffractive element operating in reflection
• CPC Class Codes: G02B 6/29314 by moving or modifying the diffractive element, e.g. deforming
• CPC Class Codes: G02B 6/2938 for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM

Abstract

A dynamic equalizing optical channel router includes an input port for receiving a wavelength division multiplexed composite optical signal comprising a plurality of channels; at least one output port; a diffraction grating optically coupled to the input and output ports; a lens optically coupled to the diffraction grating at a side opposite to the input and output ports; an array of steering devices optically coupled to the lens at a side opposite to the diffraction grating, wherein each channel is reflected by a different steering device of the array; and a plurality of attenuators, wherein each channel reflected by the array traverses one of the attenuators and the diffraction grating to the at least one output port. The router is able to dynamically adjust optical intensity of each wavelength channel by a different amount while also performing the function of wavelength routing.

Claims

1. A dynamic equalizing wavelength router, comprising:

an input port for receiving a wavelength division multiplexed composite optical signal comprising a plurality of channels;

at least one output port;

a diffraction grating optically coupled to the input and output ports;

a lens optically coupled to the diffraction grating at a side opposite to the input and output ports;

an array of steering devices optically coupled to the lens at a side opposite to the diffraction grating, wherein each channel is reflected by a different steering device of the array; and

a plurality of polarizers, wherein each channel reflected by the array traverses one of the polarizers and the diffraction grating to the at least one output port.

2. The router of claim 1, wherein the array of steering devices comprises an array of micro-mirrors, wherein each channel is focused onto a different micro-mirror, wherein a position of each micro-mirror is independently controlled.

3. The router of claim 1, wherein the array of steering devices comprises an array of polarization steering devices.

4. The router of claim 3, wherein each of the polarization steering devices comprises:

a polarization modulator optically coupled to the lens at a side opposite to the diffraction grating, wherein the polarization modulator comprises first, second, and third segments, wherein the first, second and third segments are independently controlled, wherein the lens focuses a channel of the composite optical signal through the second segment;

a birefringent polarization beam displacer optically coupled to the polarization modulator at a side opposite to the lens; and

an angled reflector optically coupled to the birefringent polarization beam displacer at a side opposite to the polarization modulator,

wherein the angled reflector comprises a first reflective surface and a second reflective surface,

wherein a channel reflected by the first reflective surface traverses the first segment of the polarization modulator, wherein a channel reflected by the second reflective surface traverses the third segment of the polarization modulator.

5. The router of claim 1, wherein the array of steering devices comprises:

a segmented polarization modulator optically coupled to the lens at a side opposite to the diffraction grating, the segmented polarization modulator comprising a first polarization modulator array comprising a first plurality of segments, and a second polarization modulator array comprising a second plurality of segments, wherein each segment of the first and second plurality of segments are independently controlled, wherein the lens focuses each channel onto a different segment of the first plurality of segments;

a Wollaston prism optically coupled to the segmented polarization modulator at a side opposite to the lens;

a second lens optically coupled to the Wollaston prism at a side opposite to the segmented polarization modulator; and

an angled mirror optically coupled to the second lens comprising a first reflective surface and a second reflective surface.

6. The router of claim 5, further comprising of attenuators including a first optical wedge optically coupled to the second lens and the first surface of the angled mirror, and a second optical wedge optically coupled to the second lens and the second surface of the angled mirror, wherein each channel traversing the first optical wedge and the second optical wedge traverses a different segment of the second plurality of segments of the segmented polarization modulator.

7. The router of claim 1, further comprising:

a half-wave plate optically coupled to the diffraction grating at a side opposite to the lens; and

a birefringent beam displacer optically coupled to the half-wave plate at a side opposite to the diffraction grating.

8. A dynamic equalizing wavelength router, comprising:

an input port for receiving a wavelength division multiplexed composite optical signal comprising a plurality of channels;

at least one output port;

a diffraction grating optically coupled to the input and output ports;

a lens optically coupled to the diffraction grating at a side opposite to the input and output ports;

an array of polarization steering devices, wherein each channel is focused onto a different steering device, wherein each of the polarization steering device comprises;

a polarization modulator optically coupled to the lens at a side opposite to the diffraction grating, wherein the polarization modulator comprises first, second, and third segments, wherein the first, second and third segments are independently controlled, wherein the lens focuses a channel of the composite optical signal through the second segment,

a birefringent polarization beam displacer optically coupled to the polarization modulator at a side opposite to the lens, and

an angled reflector optically coupled to the birefringent polarization beam displacer at a side opposite to the polarization modulator,

wherein the angled reflector comprises a first reflective surface and a second reflective surface, wherein a channel reflected by the first reflective surface traverses the first segment of the polarization modulator, wherein a channel reflected by the second reflective surface traverses the third segment of the polarization modulator; and

a plurality of polarizers, wherein each channel reflected by the array traverses one of the polarizers and the diffraction grating to the at least one output port.

9. A dynamic equalizing wavelength router, comprising:

an input port for receiving a wavelength division multiplexed composite optical signal comprising a plurality of channels;

at least one output port;

a diffraction grating optically coupled to the input and output ports;

a first lens optically coupled to the diffraction grating at a side opposite to the input and output ports;

an array of polarization steering devices, comprising;

a segmented polarization modulator optically coupled to the first lens at a side opposite to the diffraction grating, the segmented polarization modulator comprising a first polarization modulator array comprising a first plurality of segments, and a second polarization modulator array comprising a second plurality of segments, wherein each segment of the first and second plurality of segments are independently controlled, wherein the first lens focuses each channel onto a different segment of the first plurality of segments,

a Wollaston prism optically coupled to the segmented polarization modulator at a side opposite to the first lens,

a second lens optically coupled to the Wollaston prism at a side opposite to the segmented polarization modulator, and

an angled mirror optically coupled to the second lens comprising a first reflective surface and a second reflective surface;

a first optical wedge optically coupled to the second lens and the first surface of the angled mirror; and

a second optical wedge optically coupled to the second lens and the second surface of the angled mirror, wherein each channel traversing the first optical wedge and the second optical wedge traverse a different segment of the second plurality of segments of the segmented polarization modulator and the diffraction grating to the at least one output port.

10. A system, comprising:

a wavelength division multiplexed composite optical signal comprising a plurality of channels, wherein the channels comprise unequal intensities; and

a dynamic equalizing wavelength router, comprising;

an input port for receiving the optical signal,

at least one output port,

a diffraction grating optically coupled to the input and output ports,

a lens optically coupled to the diffraction grating at a side opposite to the input and output ports,

an array of polarization steering devices optically coupled to the lens at a side opposite to the diffraction grating, wherein each channel is reflected by a different steering device of the array, wherein each of the polarization steering devices comprises;

a polarization modulator optically coupled to the lens at a side opposite to the diffraction grating, wherein the polarization modulator comprises first, second, and third segments, wherein the first, second, and third segments are independently controlled, wherein the lens focuses a channel of the composite optical signal through the second segment;

a birefringent polarization beam displacer optically coupled to the polarization modulator at a side opposite to the lens; and

an angled reflector optically coupled to the birefringent polarization beam displacer at a side opposite to the polarization modulator,

wherein the angled reflector comprises a first reflective surface and a second reflective surface and wherein a channel reflected by the first reflective surface traverses the first segment of the polarization modulator, wherein a channel reflected by the second reflective surface traverses the third segment of the polarization modulator, and

a plurality of attenuators, wherein each channel reflected by the array traverses one of the attenuators and the diffraction grating to the at least one output port as an attenuated wavelength division multiplexed composite optical signal, wherein the channels of the attenuated optical signal comprise approximately equal intensities.

11. The system of claim 10, wherein the plurality of attenuators comprises a plurality of polarizers.